Plinian eruptions are violent explosive volcanic eruptions with tall ash cloud columns. They are named after Pliny the Younger who wrote a detailed account of the eruption of Vesuvius in AD79. He likened the tall eruption cloud to an umbrella pine- tall slender trunk and large spreading top.
Eruption clouds can extend well above 11km into the atmosphere and produce vast quantities of ash and gas.When the column looses its upward momentum it collapses back down the slopes of the volcano creating pyroclastic flows. Ash and pumice fall may be deep enough to bury homes,collapse roofs and turn day to night. Lahars may form where ash and water mix burying everything in their path.
Pompeii and Hercalaneum were famously buried in AD79 and the last eruption of Vesuvius was in 1944. Mt. Pinatubo, in the Phillipines,was the worlds last dramatic plinian erption in 1991. Due to the proximity of an american airbase the voclano wa closely monitored and 1000s of locals evacuated to safety. Although the lahars and refugee camps caused many fatalities.